Projectile



J. McF. ROGERS.

PROJECTILE. APPLICATION FILED JAN. I8. l9l8.

1 3307,41 9. Patented June 24, 1919.

JOSEPH MGFARLANE ROGERS, F LOUISVILLE, KENTUCKY.

PROJECTILE.

Specification of Letters Patent. Patented June 24, 1919.

Application filed January 18, 1918. Serial No. 212,437.

' To all whom it may concern:

Be it known that I. JosnrH M. Roenns,

the city of Louisville, county of Jefferson, and State of Kentucky, have invented certain new and useful Improvements in Projectiles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a projectile.

The primary object of the invention resides in the provision of a projectile of such construction that the maximum speed, range and accuracy of firing is obtained.

In the drawing:

Figure 1 is an elevation of one form of the projectile, and

Fig. 2 .is a similar view of a modified form.

In Fig. l of the drawing I have illustrated a projectile which is provided with a tapered forward end 1 and a cylindrical body portion 2. In the surface of the projectile, a helical groove is formed, the front wall 3 of which groove is perpendicular to the longitudinal axis of the projectile and the rear wall 4 of which is curved rearwardly until it merges'into the surface of the projectile.

The projectile illustrated in Fig. 2 is of the same general form as that illustrated in Fig. 1, but is provided with a pair of circular grooves, which number may, however, be increased or decreased a will. The front walls 5 of these grooves are perpendicular to the longitudinal axis of the projectile, while the rear walls 6 of the same curve toward the rear of the projectile until they merge with the surface of the projectile.

When the projectile of either form illustrated in the drawing is passing through the barrel of the gun, there will be a great compression of the atmosphere about the projectile due to the speed of the projectile and the rifling on the surface thereof, so

that the friction between the surface of the projectile and the barrel of the gun will be reduced to a minimum and consequently but a small portion of the speed of the projectile will be destroyed during the passage of the same through the gun. Furthermore, as the projectile passes through the atmosphere after having left the-gun, the air which is entrapped in the grooves or rifling in the surface of the projectile, will be rarefied because of the speed of the projectile, so that there will be. a tendency to form a vacuum within the grooves or rifling. This rarefaction of the air will greatly reduce the friction between the projectile and the atmosphere, so that speed of the projectile as well as the distance through which it travels will be greatly enhanced. Then, again, the presence of the rifling on the surface of the projectile will insure greater accuracy in firing.

While the rifling of the surface of the projectile will act equally as well on a solid projectile as one bearing an explosive charge as far as the speed, distance of travel and accuracy are concerned, the rifling will serve an additional function when an explosive charge is carried lb the projectile, in that it will insure the hreaking up of the projectile into a greater number of fragments.

What I claim is:

1. A projectile having a groove in the face thereof, the front wall of such groove being perpendicular to the longitudmal axis of the projectile, and the rear wall thereof curving toward the rear of the projectile and merging with the surface of the same.

2. A projectile having a helical, groove in the face thereof, which groove extends completely around the projectile and the rear wall of which inclines toward the rear of the projectile and merges with the surface thereof, the front wall of the groove forming with the rear wall an angle less than an obtuse angle.

In testimony whereof I aifix my signature.

JOSEPH MOFARIJANE ROGERS.

- Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). 0. 

